Can oral vitamin K before elective surgery substitute for preoperative heparin bridging in patients on vitamin K antagonists?

The effect of administering preprocedural VITamin K on the international normalized ratio in patients anticoagulated with ACEnocoumarol (VITKACE-study): a prospective cohort study

BACKGROUND

The effect of the vitamin K antagonist acenocoumarol on coagulation needs to be reversed when patients undergo an invasive procedure with considerable bleeding risk. A strategy to achieve this is by administering oral vitamin K before a procedure while continuing acenocoumarol.

OBJECTIVES

To assess the effect on periprocedural international normalized ratio (INR) values and safety using oral vitamin K as anticoagulant reversal method.

METHODS

In this prospective cohort study, consecutive patients using acenocoumarol undergoing elective procedures between 2019 and 2022 were included. According to standard of care in our hospital, patients took 10 mg oral vitamin K 36 to 48 hours before the procedure while continuing their normal use of acenocoumarol. Effectiveness to lower INR to <1.8 preprocedural was assessed. Bleeding and thrombotic complications within 30 days after the procedure were assessed. Periprocedural course of INR was monitored by collecting additional blood samples.

RESULTS

Seventy-four patients were included for analysis. On the day of the procedure, an adequate INR of <1.8 was achieved in 99% of patients. One clinically relevant nonmajor bleeding complication and no thrombotic complications were observed during the first 30 days after the procedure. INR gradually restored to therapeutic level during the days after the procedure.

CONCLUSION

Using oral vitamin K while patients continue acenocoumarol intake is an effective way to adequately lower INR before an invasive procedure. Low amount of bleeding complications and absence of thromboembolic complications suggest that this is a safe strategy. The INR values returned gradually to therapeutic range after the procedure, probably contributing to the observed low bleeding rate.

Perioperative Management of Vitamin K Antagonists and Direct Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND

The management of patients who are receiving chronic oral anticoagulation therapy and require an elective surgery or an invasive procedure is a common clinical scenario.

RESAERCH QUESTION

What is the best available evidence to support the development of American College of Chest Physicians guidelines on the perioperative management of patients who are receiving long-term vitamin K agonist (VKA) or direct oral anticoagulant (DOAC) and require elective surgery or procedures?

STUDY DESIGH AND METHODS

A literature search including multiple databases from database inception through July 16, 2020, was performed. Meta-analyses were conducted when appropriate.

RESULTS

In patients receiving VKA (warfarin) undergoing elective noncardiac surgery, shorter (< 5 days) VKA interruption is associated with an increased risk of major bleeding. In patients who required VKA interruption, heparin bridging (mostly with low-molecular-weight heparin [LMWH]) was associated with a statistically significant increased risk of major bleed (relative risk [RR], 9.1; 95% CI, 1.62-51.3), representing a very low certainty of evidence (COE). Compared with DOAC interruption 1 to 4 days before surgery, continuing DOACs was not associated with a statistically significant difference in the risk of bleeding, representing a very low COE. Continuing dabigatran was associated with a statistically significant increased risk of thromboembolism (RR, 2.2; 95% CI, 1.3-3.8), representing a low COE. In patients who needed DOAC interruption, bridging with LMWH was associated a with statistically significant increased risk of minor bleeding compared with no bridging (RR, 1.7; 95% CI, 1.13-2.7), representing a low COE.

INTERPRETATION

The certainty in the evidence supporting the perioperative management of anticoagulants remains limited. No high-quality evidence exists to support the practice of heparin bridging during the interruption of VKA or DOAC therapy for an elective surgery or procedure or for the practice of interrupting VKA therapy for minor procedures, including cardiac device implantation, or continuation of a DOAC vs short-term interruption of a DOAC (1-4 days) in the perioperative period.

Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline

BACKGROUND

The American College of Chest Physicians Clinical Practice Guideline on the Perioperative Management of Antithrombotic Therapy addresses 43 Patients-Interventions-Comparators-Outcomes (PICO) questions related to the perioperative management of patients who are receiving long-term oral anticoagulant or antiplatelet therapy and require an elective surgery/procedure. This guideline is separated into four broad categories, encompassing the management of patients who are receiving: (1) a vitamin K antagonist (VKA), mainly warfarin; (2) if receiving a VKA, the use of perioperative heparin bridging, typically with a low-molecular-weight heparin; (3) a direct oral anticoagulant (DOAC); and (4) an antiplatelet drug.

METHODS

Strong or conditional practice recommendations are generated based on high, moderate, low, and very low certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology for clinical practice guidelines.

RESULTS

A multidisciplinary panel generated 44 guideline recommendations for the perioperative management of VKAs, heparin bridging, DOACs, and antiplatelet drugs, of which two are strong recommendations: (1) against the use of heparin bridging in patients with atrial fibrillation; and (2) continuation of VKA therapy in patients having a pacemaker or internal cardiac defibrillator implantation. There are separate recommendations on the perioperative management of patients who are undergoing minor procedures, comprising dental, dermatologic, ophthalmologic, pacemaker/internal cardiac defibrillator implantation, and GI (endoscopic) procedures.

CONCLUSIONS

Substantial new evidence has emerged since the 2012 iteration of these guidelines, especially to inform best practices for the perioperative management of patients who are receiving a VKA and may require heparin bridging, for the perioperative management of patients who are receiving a DOAC, and for patients who are receiving one or more antiplatelet drugs. Despite this new knowledge, uncertainty remains as to best practices for the majority of perioperative management questions.

Perioperative management of anticoagulation

Periprocedural management of the anticoagulated patient can be as easy as continuing warfarin for a low bleeding risk procedure, holding a direct oral anticoagulant for 1 day prior and resuming 1 day later or as complex as emergent reversal with prothrombin complex concentrate, idarucizumab, or andexanet alfa. Patient-specific factors for thromboembolic risk and procedural bleeding risk determine timing of anticoagulation hold prior to and resumption after invasive procedures. Clinical trials and management studies in recent years have helped inform our approach to these patients, but much of the guidance is still based on expert consensus.

Periprocedural Management of Oral Anticoagulation

Decisions surrounding periprocedural anticoagulation management must balance thromboembolic and procedural bleed risk. The interruption of both warfarin and DOACs requires consideration of anticoagulant pharmacokinetics, procedural bleed risk and patient characteristics. There is a diminishing role for periprocedural bridging LMWH overall and no role for bridging LMWH for the procedural interruption of DOACs. A clinical approach to perioperative DOAC management based on operative bleeding risk and renal function is safe and effective, and at present, is preferred over preprocedural DOAC levels testing. Clear communication of the anticoagulation interruption plan to both the patient and the patient's care team is essential.

Validation of an algorithm to predict decline in INR following warfarin cessation in patients undergoing invasive procedures

Patients on warfarin are required to withdraw from treatment for a fixed period (normally 5 days) prior to an invasive procedure. However, the anticoagulant effect of warfarin subsides at different rates among different patients, exposing some to increased risk of either thrombosis or bleeding. In a recent study in patients awaiting surgery, following warfarin cessation the INR declined slower over time in those with two CYP2C9 variant alleles, increasing age, weight and number of comorbidities and that INR decline was faster in those with higher maintenance INR value. Subsequently, we developed an algorithm which predicts INR decline in individual patients after 5 days of warfarin cessation. The current study validated the algorithm. An independent cohort of patients completing a short course of warfarin took part in the study. INR values for subsequent 9 days and CYP2C9 genotype were available. The predicted INR decline (INR_{day 1}–INR_{day 5}) was compared to the observed one (where an INR check on day 5 was unavailable, INR was estimated using a linear approximation model). There was a strong correlation between the decline in INR by day 5 and that predicted from the algorithm for the 117 patients (r = 0.949, p < 0.001). The algorithm was precise, with low degree of bias and variance of the prediction error. The algorithm can accurately predict the INR decline following warfarin cessation in individual adult patients. The use of this easily adoptable algorithm can reduce cancellation or delays of planned surgical procedures.

Anticoagulation Use prior to Common Dental Procedures: A Systematic Review

Currently, the number of patients on oral anticoagulation is increasing. There is a paucity of data regarding maintaining oral anticoagulation (especially novel oral anticoagulants) around the time of specific dental procedures. A dentist has three options: either to stop anticoagulation, to continue it, or to bridge with heparin. A systematic review of 10 clinical trials was conducted to address this issue. It was found that continuing anticoagulation during dental procedures did not increase the risk of bleeding in most trials. Although none of the studies reported a thromboembolic event after interruption of anticoagulation, the follow-up periods were short and inconsistent, and the heightened thromboembolic risk when stopping anticoagulation is well known in the literature. Heparin bridging was associated with an increased bleeding incidence. We recommend maintaining oral anticoagulation with vitamin K antagonists and novel oral anticoagulants for the vast majority of dental procedures along with the use of local hemostatic agents.

Safety of Anticoagulation Interruption in Patients Undergoing Surgery or Invasive Procedures: A Systematic Review and Meta-analyses of Randomized Controlled Trials and Non-randomized Studies

BACKGROUND

The safety of anticoagulation interruption in patients requiring surgical or invasive procedures remains unclear. We thus performed a systematic review and meta-analyses of randomized controlled trials (RCTs) and non-randomized studies (NRS).

METHODS

MEDLINE, Embase and Central databases were searched to March 2017 without date or language restrictions. We considered RCTs and NRS comparing anticoagulation interruption with any anticoagulation (continuation or heparin bridging) in adult surgical patients taking oral anticoagulation. Data were independently extracted. The quality of the evidence was assessed following recommendations from the Cochrane collaboration (GRADE approach). Risk ratios were calculated for 30-day events: thromboembolic (TE) events, major bleeding and mortality. Additional analyses explored the effects of different anticoagulation strategies.

RESULTS

Twelve reports were included: 4 RCTs (2190 participants) and 8 NRS (18993 participants). Trials included mostly participants with atrial fibrillation. Interrupting anticoagulation did not seem to increase TE events (RR 0.65, 95% CI [0.33, 1.30]-4 studies, 2190 participants) and resulted in less bleeding (RR 0.41, 95% CI [0.22, 0.78]-3 studies, 2126 participants) compared to anticoagulation continuation or heparin bridging. The GRADE assessment was moderate. Similar results were found in non-randomized studies, but the quality of the evidence was low. Possible strategy-specific effects were identified: forgoing heparin bridging seemed beneficial, but these effects were less clear with other strategies.

CONCLUSION

Interrupting anticoagulation in patients requiring invasive procedures did not seem to result in harm and protected against major bleeding. Uncertainty remains regarding the safety of this strategy in indications other than atrial fibrillation and in moderate- to high-risk surgery.

STUDY REGISTRATION

http://www.en.anaesthesie.usz.ch/research/Pages/Study-protocols.aspx.

Indications and Methods of Anticoagulation Reversal

The use of anticoagulation in the prevention of strokes due to atrial fibrillation or the treatment of venous thromboembolic disease has been on the rise. With the advent and proliferation of direct oral anticoagulation medications, the management of anticoagulation reversal has become increasingly complex, especially when urgent or emergent reversal is required. This review details the commonly used parenteral and oral anticoagulants, the treatment strategies necessary for their reversal, and therapies still in development.

Management of anticoagulation in hip fractures: A pragmatic approach

Hip fractures are common and increasing with an ageing population. In the United Kingdom, the national guidelines recommend operative intervention within 36 hours of diagnosis. However, long-term anticoagulant treatment is frequently encountered in these patients which can delay surgical intervention. Despite this, there are no set national standards for management of drug-induced coagulopathy pre-operatively in the context of hip fractures.

The aim of this study was to evaluate the management protocols available in the current literature for the commonly encountered coagulopathy-inducing agents.

We reviewed the current literature, identified the reversal agents used in coagulopathy management and assessed the evidence to determine the optimal timing, doses and routes of administration.

Warfarin and other vitamin K antagonists (VKA) can be reversed effectively using vitamin K with a dose in the range of 2 mg to 10 mg intravenously to correct coagulopathy.

The role of fresh frozen plasma is not clear from the current evidence while prothrombin complex remains a reliable and safe method for immediate reversal of VKA-induced coagulopathy in hip fracture surgery or failed vitamin K treatment reversal.

The literature suggests that surgery should not be delayed in patients on classical antiplatelet medications (aspirin or clopidogrel), but spinal or regional anaesthetic methods should be avoided for the latter. However, evidence regarding the use of more novel antiplatelet medications (e.g. ticagrelor) and direct oral anticoagulants remains a largely unexplored area in the context of hip fracture surgery. We suggest treatment protocols based on best available evidence and guidance from allied specialties.

Hip fracture surgery presents a common management dilemma where semi-urgent surgery is required. In this article, we advocate an evidence-based algorithm as a guide for managing these anticoagulated patients.

Cite this article: EFORT Open Rev 2017;2:394–402. DOI: 10.1302/2058-5241.2.160083

Reversing vitamin K antagonists: making the old new again

Vitamin K antagonists (VKAs) are commonly used for the prevention and treatment of thrombotic disorders. The response to VKAs is highly variable due to their specific interaction with the vitamin K cycle, and hence interference with hepatic synthesis of vitamin K-dependent coagulation factors. Monitoring the anticoagulant effect of VKAs by assessing the patient's international normalized ratio (INR) is essential because complications are closely related to the intensity of anticoagulation. Treatment with VKAs contains a substantial risk of bleeding with a high case fatality rate. Reversal of VKAs is required in case of bleeding or a supratherapeutic INR, but also prior to high-risk surgery or interventions. Choice of methods to reverse VKAs depends on whether or not the patient is bleeding or is in need of an urgent procedure, and has to be based on the pharmacokinetic and pharmacodynamic properties of the VKA. Reversal strategies include withholding the VKA, administration of vitamin K₁, and substitution of vitamin K-dependent procoagulant factors, and need to be combined with measures according to general bleeding management.

Budget impact analysis of warfarin reversal therapies among hip fracture patients in Finland

BACKGROUND

Hip fractures require operation within 36-48 h, and they are most common in the elderly. A high International Normalized Ratio should be corrected before surgery. In the current study, we analyzed the budget impact of various warfarin reversal approaches.

METHODS

Four reversal strategies were chosen for the budget impact analysis: the temporary withholding of warfarin, administration of vitamin K, fresh frozen plasma (FFP), and a four-factor prothrombin complex concentrate (PCC).

RESULTS

We estimated that, annually, 410 hip fracture patients potentially require warfarin reversal in Finland. The least costly treatment was vitamin K, which accounted for €289,000 in direct healthcare costs, and the most costly treatment option was warfarin cessation, which accounted for €1,157,000. In the budget impact analysis, vitamin K, PCC and FFP would be cost-saving to healthcare compared with the current treatment mix.

CONCLUSION

The various warfarin reversal strategies have different onset times, which may substantially impact the subsequent healthcare costs.

Extra-pericardial tamponade following Wolf Mini-Maze procedure: a case report

Background

Extra-pericardial tamponade is a rare life threatening condition that has not previously been reported in association with Wolf Mini-Maze procedures. In this case, atypical presentation of cardiac tamponade caused by postoperative anticoagulation resulted in a second hospitalization, a second surgery, and delayed recovery time. The goal of this case report is to increase awareness about a life threatening complication that can occur following minimally invasive cardiac surgery.

Case Presentation

A 60 year old male with long standing essential hypertension, who was recently treated for atrial fibrillation utilizing the Wolf Mini-Maze procedure, experienced a postoperative international normalized ratio increase from 3.6 to 5.3 over the course of six days. Fifteen days postoperatively, the patient experienced mild exercise intolerance, his condition rapidly progressed to a constellation of symptoms including severe exercise intolerance, dyspnea, hypotension, and near syncope. A diagnosis of cardiac tamponade was made, and the patient was re-admitted to the hospital. Attempts to reverse his warfarin anticoagulation with fresh frozen plasma and vitamin K were unsuccessful after 24 h. Video-assisted thoracotomy was performed to relieve the tamponade, and during surgery he was diagnosed with extra-pericardial tamponade caused by an extensive hematoma. Complications due to anticoagulation therapy required this re-admission, additional surgery, and delayed recovery. The patient has since recovered completely with no long term morbidities and is asymptomatic three years following initial presentation.

Conclusions

This case marks the first time extra-pericardial tamponade has been reported post cardiothoracic intervention in English literature. Many surgical procedures require postoperative anticoagulation; in the past, warfarin has been the standard of care due to its purported reversibility. This case provides an example of the challenge presented when anticoagulating with warfarin, and the reversal of this anticoagulation.

Modelling of vitamin K half-life in patients treated with vitamin K antagonists before hip fracture surgery

BACKGROUND

Guidelines recommend treatment with vitamin K in patients requiring reversal of the effect of vitamin K antagonists (VKA) before semi-urgent surgery. In clinical practice, the time for reversal of the international normalized ratio (INR) to values adequate for surgery is often reported longer than the expected 12-24 hours, which may delay surgery and increase the risk of complications.

METHODS

In order to optimize the management of elderly patients treated with VKA and undergoing hip fracture surgery, we aimed to model the vitamin K half-life in this specific population. Files for patients admitted between 2006 and 2008 for hip fracture surgery and chronically treated with VKA were retrospectively studied. Only patients with an INR superior to 1.5 upon arrival were included in the study. The effect of vitamin K on the decrease in INR was modelled after a PK/PD analysis using NONMEM. Thirty-one patients' files were analysed.

RESULTS

Despite management in accordance with guidelines, 31% of the patients had a delayed return to INR values<1.5 resulting in delayed surgery. Time to INR<1.5 was longer than 24 hours in 50% of the patients. The calculated half-life of vitamin K was 24.7 hours in this population.

CONCLUSION

The vitamin K half-life in elderly patients treated with VKA and undergoing hip fracture surgery was prolonged. The use of vitamin K or of a more rapid acting alternative should be discussed, depending on the urgency of the surgery.

Influence of CYP2C9 polymorphism on the fall in International Normalized Ratio in patients interrupting warfarin therapy before elective surgery

BACKGROUND

Patients on warfarin are normally required to stop treatment for a fixed number of days prior to an invasive procedure. However, the anticoagulant activity of warfarin subsides at different rates among different patients.

OBJECTIVES

The aim of this study was to investigate the potential influence of CYP2C9 polymorphism on the variable rate of fall in the International Normalized Ratio (INR) in patients withdrawing from warfarin treatment prior to elective surgery.

PATIENTS/METHODS

One hundred and fifty-two patients aged 43-93 years were recruited. Demographic data on age, height, weight, gender, daily warfarin dose, indication for anticoagulation therapy, medical diagnosis, surgical operation planned and concomitant medication were recorded. A blood sample was taken for later CYP2C9 genotyping.

RESULTS

For patients with two CYP2C9 variant alleles (CYP2C9*2*2 or CYP2C9*2*3), the odds of having an INR of ≥ 1.5 before the planned day of surgery were 8.64 times greater (95% confidence interval [CI] 2.25-33.25) than for other patients. Multiple regression analysis revealed that the rate of fall in the INR was reduced in the presence of two CYP2C9 variant alleles, as well as increasing patient age, weight and number of comorbidities, and increased with increasing initial INR (F5,132  = 242.9, P < 0.0001), all of which accounted for ~ 90% of the interindividual variability in the fall in INR.

CONCLUSION

A genotype-guided protocol to tailor warfarin withdrawal according to an individual patient's CYP2C9 genotype could reduce cancellation or delays of planned procedures, and could also be beneficial when transitioning patients from warfarin to one of the new oral anticoagulants.

The impact of genetics on the management of patients on warfarin awaiting surgery

Two older patients with atrial fibrillation, receiving warfarin for thromboembolic prophylaxis, with a target range of 2.0-3.0, were significantly over anticoagulated prior to elective intervention, in spite of having adhered to the standard protocol of 5 days of warfarin interruption. Neither patient had any abnormality of liver function nor was taking any interacting drug known to inhibit warfarin metabolism or affect sensitivity to warfarin. Both had variant cytochrome P2C9 (CYP2C9) alleles which reduce the metabolic capacity of the CYP2C9 enzyme responsible for the metabolism of the S-warfarin enantiomer. Need for preoperative administration of vitamin K or postponement of an operation because of an INR >1.5 could be explained by variant alleles for CYP2C9 and age.

The effect of preoperative vitamin K on the INR in bridging therapy

We investigated a bridging protocol using oral Vitamin K three days before scheduled surgery. 60 patients in two bridging protocols, 30 cases per protocol. The first cohort (Control group) had its warfarin held on Day-5 (five days before surgery). The intervention cohort (Vitamin K group) routinely received 2.5 mg of oral Vitamin K on Day-3 but was otherwise identically bridged. Primary outcome was INR on Day-1. Secondary outcomes included patients with INRs ≥1.5 on Day-1, bleeding episodes and elevated INR post surgery. Day-1 INR for the Vitamin K group was 1.16, vs. 1.28 for the Control group (p = 0.037). Postoperative INR was similar. Only the Control group had patients with INRs ≥1.5 on Day-1, or patients with significant bleeding. Adding Vitamin K on Day-3 leads to a safe preoperative INR and may limit other complications.

Perioperative management of patients on chronic antithrombotic therapy

Perioperative management of antithrombotic therapy is a situation that occurs frequently and requires consideration of the patient, the procedure, and an expanding array of anticoagulant and antiplatelet agents. Preoperative assessment must address each patient's risk for thromboembolic events balanced against the risk for perioperative bleeding. Procedures can be separated into those with a low bleeding risk, which generally do not require complete reversal of the antithrombotic therapy, and those associated with an intermediate or high bleeding risk. For patients who are receiving warfarin who need interruption of the anticoagulant, consideration must be given to whether simply withholding the anticoagulant is the optimal approach or whether a perioperative “bridge” with an alternative agent, typically a low-molecular-weight heparin, should be used. The new oral anticoagulants dabigatran and rivaroxaban have shorter effective half-lives, but they introduce other concerns for perioperative management, including prolonged drug effect in patients with renal insufficiency, limited experience with clinical laboratory testing to confirm lack of residual anticoagulant effect, and lack of a reversal agent. Antiplatelet agents must also be considered in the perioperative setting, with particular consideration given to the potential risk for thrombotic complications in patients with coronary artery stents who have antiplatelet therapy withheld.

Perioperative management of patients on chronic antithrombotic therapy

Perioperative management of antithrombotic therapy is a situation that occurs frequently and requires consideration of the patient, the procedure, and an expanding array of anticoagulant and antiplatelet agents. Preoperative assessment must address each patient's risk for thromboembolic events balanced against the risk for perioperative bleeding. Procedures can be separated into those with a low bleeding risk, which generally do not require complete reversal of the antithrombotic therapy, and those associated with an intermediate or high bleeding risk. For patients who are receiving warfarin who need interruption of the anticoagulant, consideration must be given to whether simply withholding the anticoagulant is the optimal approach or whether a perioperative "bridge" with an alternative agent, typically a low-molecular-weight heparin, should be used. The new oral anticoagulants dabigatran and rivaroxaban have shorter effective half-lives, but they introduce other concerns for perioperative management, including prolonged drug effect in patients with renal insufficiency, limited experience with clinical laboratory testing to confirm lack of residual anticoagulant effect, and lack of a reversal agent. Antiplatelet agents must also be considered in the perioperative setting, with particular consideration given to the potential risk for thrombotic complications in patients with coronary artery stents who have antiplatelet therapy withheld.

Perioperative management of antithrombotic therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline addresses the management of patients who are receiving anticoagulant or antiplatelet therapy and require an elective surgery or procedure.

METHODS

The methods herein follow those discussed in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.

RESULTS

In patients requiring vitamin K antagonist (VKA) interruption before surgery, we recommend stopping VKAs 5 days before surgery instead of a shorter time before surgery (Grade 1B). In patients with a mechanical heart valve, atrial fibrillation, or VTE at high risk for thromboembolism, we suggest bridging anticoagulation instead of no bridging during VKA interruption (Grade 2C); in patients at low risk, we suggest no bridging instead of bridging (Grade 2C). In patients who require a dental procedure, we suggest continuing VKAs with an oral prohemostatic agent or stopping VKAs 2 to 3 days before the procedure instead of alternative strategies (Grade 2C). In moderate- to high-risk patients who are receiving acetylsalicylic acid (ASA) and require noncardiac surgery, we suggest continuing ASA around the time of surgery instead of stopping ASA 7 to 10 days before surgery (Grade 2C). In patients with a coronary stent who require surgery, we recommend deferring surgery > 6 weeks after bare-metal stent placement and > 6 months after drug-eluting stent placement instead of undertaking surgery within these time periods (Grade 1C); in patients requiring surgery within 6 weeks of bare-metal stent placement or within 6 months of drug-eluting stent placement, we suggest continuing antiplatelet therapy perioperatively instead of stopping therapy 7 to 10 days before surgery (Grade 2C).

CONCLUSIONS

Perioperative antithrombotic management is based on risk assessment for thromboembolism and bleeding, and recommended approaches aim to simplify patient management and minimize adverse clinical outcomes.

Perioperative management of patients receiving anticoagulant or antiplatelet therapy: a clinician-oriented and practical approach

The management of patients who are receiving warfarin, aspirin, clopidogrel, or combinations of these drugs and require their interruption because of an elective surgical or other invasive procedure is a common and sometimes challenging clinical problem. For the practicing clinician, there are 2 key issues for perioperative anticoagulant management: 1) having an approach to stratify patients according to their risk for thromboembolism when warfarin or antiplatelet drug therapy is interrupted, and also having an approach to stratify patients according to the risk of bleeding associated with the surgery or procedure; and 2) determining which patients may require bridging anticoagulation and, if required, how to administer bridging, typically with a low-molecular-weight heparin, before and after surgery in a manner that minimizes the risk for bleeding. The overall goal is to minimize patients' risk for thromboembolism and bleeding throughout the perioperative period. The objective of this article is to provide an evidence-based but practical approach relating to these 2 key issues in a manner than can be applied to everyday clinical practice.

Using Prothrombin Complex Concentrates to Rapidly Reverse Oral Anticoagulant Effects

Warfarin is a commonly prescribed anticoagulant that may, in selected situations, require rapid reversal of its effects. Several approaches to achieve reversal have been explored, including the administration of prothrombin complex concentrates (PCCs), Many factors can influence determination of an appropriate PCC dose and the resulting effects. Considerations on the use of PCC products to expedite the reversal of warfarin are described.

French clinical practice guidelines on the management of patients on vitamin K antagonists in at-risk situations (overdose, risk of bleeding, and active bleeding)

The present report from several French medical societies in the field and the French National Authority for Health provides an expert consensus for the management of patients on vitamin K antagonists in at-risk situations (overdose, risk of bleeding, and active bleeding). Asymptomatic VKA overdose is defined as an International Normalized Ratio (INR) value above the upper limit of the therapeutic target. In this case, the guidelines describe the rapid reduction of the INR down to the therapeutic range, either by omitting a dose or using vitamin K. Regarding the haemorrhagic complications, the guidelines address the management of these patients according to the severity of bleeding, and especially focus on the use of prothrombin complex concentrate. Finally, the consensus addresses the management of patients in cases of elective or emergency surgery or other invasive procedures, and discusses whether treatment should be continued or not, and whether VKA substitution by heparin--"bridging anticoagulation"--is needed.